In addition to an enhancement bonus, armor may have special abilities . Special abilities usually count as additional bonuses for determining the market value of an item, but do not improve AC. A suit of armor cannot have an effective bonus (enhancement plus special ability bonus equivalents, including those from character abilities and spells) higher than +10. A suit of armor with a special ability must also have at least a +1 enhancement bonus.

Special Materials: A suit of armor or a shield may be made of an unusual material.

Shields: Shield enhancement bonuses stack with armor enhancement bonuses. Shield enhancement bonuses do not act as attack or damage bonuses when the shield is used in a shield bash. The bashing special ability, however, does grant a +1 bonus on attack and damage rolls (see the special ability description).

As with armor, special abilities built into the shield add to the market value in the form of additions to the bonus of the shield, although they do not improve AC. A shield cannot have an effective bonus (enhancement plus special ability bonus equivalents) higher than +10. A shield with a special ability must also have at least a +1 enhancement bonus.

Activation: Usually a character benefits from magic armor and shields in exactly the way a character benefits from non-magical armor and shields: by wearing them. If armor or a shield has a special ability that the user needs to activate, then the user usually needs to utter the command word (a standard action).

Armor for Unusual Creatures: The cost of armor for non-humanoid creatures, as well as for creatures who are neither Small nor Medium, varies. The cost of the masterwork quality and any magical enhancement remains the same.

For example, a suit of breastplate armor (which has a +6 armor bonus) can have up to six spells inscribed on it. If you are using the piecemeal armor rules, only a piece of armor that grants an armor bonus can be spellscribed.

The maximum level for spells contained in spellscribed armor depends on the type of armor being inscribed.

Light armor, a buckler, or a light shield can hold up to 3rdlevel spells; medium armor or a heavy shield can hold up to 6th-level spells; heavy armor or a tower shield can hold up to 9th-level spells.

An inscribed spell is a spell-completion item that only the wearer of spellscribed armor may activate, and only if he is proficient with the type of armor worn. The inscribed spell vanishes when activated. The inscribed spell must be visible to the wearer and must be touched as part of its activation. Otherwise, suits of spellscribed armor are treated as scrolls (except that using them doesn’t provoke attacks of opportunity) and use the rules for spell-completion items.

Most magic armor and shields have only enhancement bonuses. Such items can also have one or more of the special abilities detailed below. Armor or a shield with a special ability must have at least a +1 enhancement bonus.